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SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
VOLUME 17 NUMBER 2 • NOVEMBER 2020
43
and cardiac ultrasound data [left ventricular ejection fraction
(LVEF) < 40% or ≥ 40%]; (3) biological data: troponin Ic and
cardiac enzymes, (4) coronary angiography findings: number of
epicardial vessels affected (one-, two- and three-vessel disease),
(5) management: dual antiplatelet therapy (DAPT), percutaneous
coronary intervention (PCI), and (6) in-hospital evolution: atrial
fibrillation, sustained ventricular tachycardia/ ventricular fibrillation,
cardiogenic shock, death.
Hypertension was defined as systolic blood pressure ≥ 140
mmHg and/or diastolic blood pressure ≥ 90 mmHg, measured three
times during hospitalisation or treatment of previously diagnosed
hypertension. DM was defined according to the American Diabetes
Association13 as one of the following criteria: glycated haemoglobin
≥ 6.5%, fasting plasma glucose ≥ 1.26 g/l (6.99 mmol/l) on two
occasions, two-hour plasma glucose ≥ 2 g/l (11.1 mmol/l) after
75-g oral glucose tolerance test (OGTT), random plasma glucose
≥ 2 g/l (11.1 mmol/l), or patients on glucose-lowering therapy on
admission. Active smoking was defined as current or interrupted
smoking for less than three years.
Dyslipidaemia was defined as total cholesterol concentration
> 2.40 g/l (6.22 mmol/l) and/or high-density lipoprotein (HDL)
cholesterol < 0.40 g/l (1.04 mmol/l) in males and < 0.50 g/l (1.3
mmol/l) in females and/or low-density lipoprotein (LDL) cholesterol
> 1.60 g/l (4.14 mmol/l), or triglyceride levels > 1.5 g/l (1.70
mmol/l). Familial history of coronary artery disease (CAD) was
defined as the occurrence of a myocardial infarction or sudden
death: before the age of 55 years in the father or in a firstdegree
male relative; and before the age of 65 years in the mother or
in a first-degree female relative. Symptom–admission delay was
the time between the onset of symptoms and admission to the
Abidjan Heart Institute.
ST-segment elevation myocardial infarction (STEMI) was defined
as the presence of symptoms or signs of myocardial ischaemia,
persistent ST-segment elevation or newly diagnosed bundle
branch block, and an increase in cardiac biomarkers beyond the
99th percentile.
6
Non-ST-elevation ACS (NSTEACS) was defined
as the presence of symptoms or signs of myocardial ischaemia,
absence of persistent ST-segment elevation, and elevation (non-
Q-wave myocardial infarction) or no elevation (unstable angina) of
cardiac biomarkers beyond the 99th percentile.
14
Left ventricular
systolic dysfunction was defined for a LVEF < 40%.
15
Statistical analysis
Continuous variables are presented as mean ± standard deviation
or median (interquartile range). Categorical data are presented
as numbers and proportions. Statistical comparisons between
groups used the Student’s
t
-test or Mann–Whitney test for
continuous variables, and the chi-squared test or Fisher’s exact
test for categorical variables. A receiver operating characteristics
(ROC) curve was performed to determine the admission glycaemic
threshold level predictive of death in our population.
Univariate and multivariate backward stepwise logistic
regressions were used to assess predictors of in-hospital death, with
an inclusion threshold of
p
< 0.20 in the multivariate analysis. The
candidate variables considered were selected according to available
data in the literature. The Wald (or Fisher) test was used to assess
the significance of hazard ratio (HR) and their 95% confidence
interval (95% CI). We defined statistical significance using a two-
sided
p
-value < 0.05. We used RStudio statistical software version
1.1.383 (Boston, MA, USA).
Results
Table 1 summarises the patients’ general characteristics and
outcomes according to blood glucose status at admission. Among
the 1 168 patients included in our study, 474 had AH, with a
prevalence of 40.6%. The average age of our study population
was 56.0 ± 11.6 years (range 21–91). Patients in the AH group
were significantly older than those in the NAH group (57.9 ±
11.0 vs 54.7 ± 11.8 years,
p
< 0.001). Patients over 60 years old
frequently had acute hyperglycaemia (40.7 vs 31.7%,
p
= 0.001).
The male gender was predominant (80.7%) with a ratio of male
to female of 4.2. Patients in the NAH group were more likely to
be female, with no significant difference (Table 1). According to
cardiovascular risk factors and history, AH patients had significant
increases in hypertension (
p
< 0.001) and DM (
p
< 0.001). Smoking
was frequently reported in the NAH group (
p
= 0.002).
The median symptom–admission delay was 19 hours (5–48).
There was no difference concerning blood glucose levels at
admission (
p
= 0.37). Heart failure often occurred in AH patients
(35.4 vs 20.7%,
p
< 0.001). AH patients presented with increased
blood pressure and heart rate. In AH patients, peaks in troponin Ic
(
p
= 0.004), creatine phosphokinase (CPK) (
p
< 0.001) and creatine
kinase-MB (CK-MB) levels (
p
< 0.001) were higher. Coronary
angiography was performed in 564 patients (48.3%). Although
there was no significant difference (
p
= 0.51), three-vessel disease
was more common in AH patients (Table 1). Two hundred and
twenty patients underwent PCI (18.8%). Dual antiplatelet therapy
(aspirin + clopidogrel) was given to 782 patients (67.0%). No
differences were reported between the groups.
Over the study period, 800 STEMI patients out of 1 138 (68.5%)
were admitted to ICU. Thrombolysis was performed in 93 patients,
in most of the cases with Alteplase (77/93, 82.8%). PCI procedures
started on 27 April 2010. One hundred and fifty-one STEMI patients
underwent PCI.
Cardiogenic shock occurred significantly in patients with acute
hyperglycaemia (
p
< 0.002). Atrial fibrillation and severe ventricular
arrhythmias (sustained ventricular tachycardia or ventricular
fibrillation) were more frequent in the AH group, without significant
difference. Overall in-hospital mortality rate was 9.1% (106/1168).
It was higher in AH patients (15.2%,
p
< 0.001) (Table 1).
In multivariate analysis, heart failure (HR = 2.22; 1.38–3.56;
p
= 0.001), LVEF < 40% (HR = 6.41; 3.72–11.03;
p
< 0.001), acute
hyperglycaemia (HR = 2.33; 1.44–3.77;
p
< 0.001), sustained
ventricular tachycardia or ventricular fibrillation (HR = 3.43; 1.37–
8.62;
p
= 0.008) and cardiogenic shock (HR = 8.82; 4.38–17.76;
p
< 0.001) were the risk factors associated with in-hospital death.
PCI (HR = 0.35; 0.16–0.79;
p
= 0.01) and dyslipidaemia (HR =
0.48; 0.27–0.84;
p
= 0.01) were identified as protective factors
(Tables 2, 3).
The sub-group analyses according to the history of DM
emphasised cardiogenic shock (HR = 23.75; 7.60–74.27;
p
< 0.001
and HR = 9.05; 3.66–22.33;
p
< 0.001, respectively) in both AH and
NAH populations as risk factors (Tables 4, 5). In patients without a
history of DM, only hyperglycaemia was associated with in-hospital
death (HR = 3.12; 1.72–5.68;
p
< 0.001) (Table 5).
We carried out a second analysis over two periods: 2002–2010
and 2011–2017. Admission hyperglycaemia was a predictive factor
only from 2011–2017 (HR = 2.57; 1.52–4.32). (Tables 6, 7).
The blood glucose threshold of 151 mg/dl (8.38 mmol/l) was
the one with the best sensitivity and specificity (area under the